/*
 * Copyright (C) 2021 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.sentry.spring;

import io.sentry.SentryOptions;
import io.sentry.protocol.User;
import io.sentry.util.Objects;

import javax.servlet.http.HttpServletRequest;

import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

/**
 * Resolves user information from {@link HttpServletRequest} obtained via {@link
 * RequestContextHolder}.
 */
public final class HttpServletRequestSentryUserProvider implements SentryUserProvider {
    private final @NotNull SentryOptions options;

    public HttpServletRequestSentryUserProvider(final @NotNull SentryOptions options) {
        this.options = Objects.requireNonNull(options, "options are required");
    }

    @Override
    public @Nullable User provideUser() {
        if (options.isSendDefaultPii()) {
            final RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
            if (requestAttributes instanceof ServletRequestAttributes) {
                final ServletRequestAttributes servletRequestAttributes =
                    (ServletRequestAttributes) requestAttributes;
                final HttpServletRequest request = servletRequestAttributes.getRequest();

                final User user = new User();
                user.setIpAddress(toIpAddress(request));
                if (request.getUserPrincipal() != null) {
                    user.setUsername(request.getUserPrincipal().getName());
                }
                return user;
            }
        }
        return null;
    }

    // it is advised to not use `String#split` method but since we do not have 3rd party libraries
    // this is our only option.
    @SuppressWarnings("StringSplitter")
    private static @NotNull String toIpAddress(final @NotNull HttpServletRequest request) {
        final String ipAddress = request.getHeader("X-FORWARDED-FOR");
        if (ipAddress != null) {
            return ipAddress.contains(",") ? ipAddress.split(",")[0].trim() : ipAddress;
        } else {
            return request.getRemoteAddr();
        }
    }
}
